Citadel
by Program Nine
Summary: The Enterprise visits a technologically-advanced civilisation that long ago gave up space travel and instead transformed their single planet into one giant city. Meanwhile, the ship is experiencing unexplained malfunctions and the Engineering personnel are talking about seeing weird things in the Jeffries Tubes...


Star Trek – The Next Generation

 **Citadel**

By Daniel Bristow-Bailey

 _Captain's Log, Stardate 42313.4: We have been invited to Trancor to open discussions about formal diplomatic relations between the reclusive Trancori people and the Federation. Little is known about the Trancori, other than that they are an old, technologically advanced civilisation that long ago gave up space travel and instead confined its entire population to a single planet. Making first contact with such a species will be a great honour, assuming we can get there at all – the Enterprise has been suffering a number of recurrent faults that seem to be baffling our Chief Engineer._

The planet Trancor grew in the viewscreen, revealing ever-increasing levels of detail in the vast structures the covered its surface. A steel-grey globe, it looked completely artificial, criss-crossed by the geometric lines of cliffs and canyons, punctuated by bristling clusters of towers, each one dozens of kilometres tall. It appeared not to have an atmosphere, at least not above the metallic surface it presented to the universe, so every detail was pin-sharp, the shadows jet-black.

"Astounding," said Captain Picard. "A planet the size of the Earth, completely covered in artificial structures. I wonder how many billions could live in such a place?"

"Theoretically," said Data, pausing a second while he did the calculations, "such a planet could house several trillion humanoid inhabitants in relative comfort, assuming a level of technology equivalent to our own. Perhaps more, depending on how deep the habitable layer extends – my preliminary scans indicate structures extending several hundred kilometres below the surface in places."

Riker, sitting next to the Captain, hailed Engineering on the comlink. "Mister LaForge, are you getting this? Quite a feat of engineering!"

"I'll have to take your word for it, sir," said Lieutenant-Commander LaForge. His voice sounded strained. "Right now I've got my own feat of engineering to pull off – these plasma conduits are degrading faster than I can replace them."

"Still?" said Riker. "I thought you fixed that."

"So did I, sir."

"When you've finished discussing the plumbing," interjected Picard. "Perhaps you might hail the Trancori government and let them know we're here."

There was a shimmer in the air as the away team materialised at the co-ordinates they had been given. The Enterprise's transporter beam couldn't penetrate deep within the planet's surface, and they'd been warned to expect freezing temperatures and thin air. Despite the warning, it still came as a shock after the air-conditioned comfort of the Enterprise. Riker pulled up the quilted hood of his coat and breathed deeply from the oxygen mask he was wearing.

They had materialised in a vast, open space, the ceiling high above them, covered in snaking ducts, just visible in the gloom. Nearby were some large pieces of machinery of no obvious purpose and apparently standing idle, covered, as was everything else, in a thick, glittering layer of frost.

A single Trancori delegate was there to meet them, apparently no more comfortable in the old than they were. Like all Trancori, as far as the Federation was aware, ey was humanoid, but slight of stature and with pure white skin and pink eyes. Shielded from the harsh light of their sun for many generations, albinism had become prevalent among the Trancori.

Ey stepped forward, smiling, and bowed first few words of eir greetings were lost while the Starfleet officers' universal translators calibrated themselves. "…celestial visitors. My name is Administrator Dolano. I apologise for the insalubrious nature of our surroundings, but these upper levels are rarely visited. If you'll follow me, an elevator is waiting…"

Dolano led them to a door that slid open to reveal a warm, brightly-lit room about fifteen metres across, with a domed ceiling and comfortable-looking, if child-sized, furniture. But for the lack of windows, it could have been the lounge of a luxury hotel on Earth. A range of snacks and refreshments was laid out on the table in the centre of the room.

"The trip will take an hour or so," said Dolano. "Please help yourselves. I hope we interpreted your nutritional requirements correctly. We have so long awaited your arrival; we want everything to be perfect."

The Starfleet officers took off their heavy coats and oxygen masks, revealing dress uniforms, as befitted a diplomatic mission. As they made themselves comfortable, Riker felt a lurch and a brief sensation of weightlessness as they started accelerating downwards. He pulled out his tricorder and checked the inertial sensors. "Over a hundred metres a second – straight down!" he exclaimed. "If the trip takes an hour, then…"

"The Presidential Complex is about three hundred kilometres down," said Dolano. "But the Habitable Zone extends far beneath that, in this region."

"Remarkable," said Picard. "The sheer scale of what your people have achieved is difficult to comprehend."

"It was born of necessity," said Dolano, "and achieved gradually, over millennia. After we turned our backs on the Outer Darkness, our population continued to grow. Our cities merely grew with it."

"I'm curious," said Riker, leaning forward to help himself to another pastry. "Why did your people give up space travel? You've clearly got the technology…"

Dolano leant back, eir lips pursed. There was a long pause. "We don't really talk about that," ey said quietly.

"We intended no offence," said Troi. "Often, when two cultures first meet…"

"…misunderstandings can arise," said Dolano, recovering eir composure somewhat. "Let us say no more about it. This should be a time of great rejoicing."

* * *

Back on the Enterprise, Commander LaForge's to-do list was only getting longer. Not only were the warp plasma conduits degrading about a thousand times faster than design specs, other components were failing in ways that shouldn't even have been possible.

He and Lieutenant Barclay were crouched in a Jeffries Tube, surveying a damaged EPS Manifold. "Just look at it!" said LaForge. "It's like it's been chewed up! I can't begin to think what would cause something like this."

"Something weird is going on," said Barclay. "Some of the other officers say they've seen strange things in the Jeffries tubes, flitting about."

LaForge put his tools down and twisted round to face Barclay, no easy feat in the confined space. "Flitting about? Are we blaming ghosts now?"

Barclay shrugged. "I didn't say I believed it myself, sir. But you have to admit it's a mystery."

"Everything's a mystery until you figure it out, Barclay," said Laforge, turning back to the EPS manifold. "Now help me uncouple these stem bolts – we're going to need to swap out the whole unit."

"Ensign Chaudhury say he saw one feeding on the plasma conduits in the port Nacelle Jeffreis Tube," said Barclay. "Sucking on them, like a vampire."

"I don't care what Ensign Chaudhury thinks he saw," said LaForge. "There's no such thing as ghosts. Or vampires."

"No-one's calling them ghosts, sir," said Barclay. "Well, only you."

"You say they appear and disappear, walk through walls; what else would you call them?"

Barclay shrugged. "Well, some of the crew have taken to calling them… Entities, sir."

"Suitably vague," said LaForge. The subject irritated him more than it should have done. Perhaps in part because he was hearing it from Barclay, whom he'd never found that easy to get on with, but also because there was a genuine mystery here, which he needed all the help of his team to figure out. All this talk of "Entities" was diverting people's attention from working out the real cause of the problem. However, it sounded like he wasn't going to be able to ignore it any longer. He replaced the access cover on the EPS manifold and sighed. "It sounds like this talk has been going on for a while."

"Since we entered this sector, sir. And it's only been getting worse, the closer we get to Trancor. People are starting to say it's cursed."

"Why am I the last guy on the ship to hear about this?"

"Well, sir, the feeling seemed to be that you, well, wouldn't take it seriously. Sir."

Geordi had to admit that Barclay had a point.

* * *

In the elevator, the conversation had grown rather stilted since Riker's faux-pas. He was looking forward to their arrival. He wasn't sure what to expect but surely, he thought, anything would be better than this.

His wish was granted with a loud bang and a screech of tearing metal. The elevator ground to a sudden and jarring halt, throwing everyone to the floor. Riker banged his nose on the way down. Didn't feel like it was broken, but it sure hurt.

Riker's nose seemed to be the most serious injury among the passengers, but the elevator had come to rest at an angle of about thirty degrees, making it difficult for people to regain their feet.

"What was that?" asked Picard. "Has the lift broken down?"

"I hope so," said Dolano, fumbling for a communicator on eir belt. "If that's all it is, then a rescue team will be here shortly and we can be on our way."

"What else could it be?" asked Riker.

Dolano didn't answer, distracted by eir attempts to get a signal on eir communicator. "Blocked," ey muttered. Ey looked up, eir eyes wide with worry. "Are any of you carrying a weapon?"

Picard shook his head. "This is a diplomatic mission. It would be a serious breach of protocol for any of us…" He trailed off as Riker produced a type-one hand phaser from an inside pocket of his dress tunic. "I thought I gave clear instructions that we were doing this by the book, Number One!"

"I'm sorry, Captain," said Riker, not, given the circumstances, feeling that sorry. "Whorf suggested it, given how little we knew about the situation down here…"

"I'll have words with Whorf when we get back," said Picard.

"I for one am grateful for your prudence," said Dolano. "It is clearly the hand of Destiny at work. You may be called upon to defend yourselves."

"From whom?" asked Picard. "Damn it, Dolano, what is it that you're not telling us?"

"A great deal, I think," said Troi, looking at Dolano's face with interest. "Captain, I think that the situation here is more complicated than we were led to believe."

"What's that noise?" asked Riker. He'd heard a bump and a scrape from outside the elevator. Everyone fell silent. There was another bump, and then a deafeningly loud bang, accompanied by a bright flash and a puff of acrid smoke. A large, square portion of the wall fell inwards, its edges glowing red. Before anyone could react, a half-dozen armed Trancori flew through the hole. At first, Riker thought they were just unusually acrobatic, but he realised they were wearing anti-gravity harnesses over body armour, their uniforms camouflaged in angular grey patterns to suit the Trancori environment. Riker, seeing that he was hopelessly outnumbered and outgunned, discreetly slid his small phaser back into his tunic.

Administrator Dolano, however, wasn't going down without a fight. Picking up a heavy bottle that had been part of the spread of refreshments, ey lunged at the nearest Trancori, wielding the bottle like a club. Ey didn't get within striking distance before the Trancori spun round and felled Dolano with a beam of blue light that knocked em convulsing to the floor.

One of the other Trancori stepped over and prodded Dolano's steaming body with eir boot. "Dead. Let that be a warning to the rest of you. Do not try our patience!" Ey turned to eir subordinates. "Harness them! We need to be gone before the rescue crew arrives!"

The trancori bound the humans' wrists and ankles before strapping them into anti-gravity harnesses like the ones they were wearing themselves – the only difference being that the humans had no control over where they were going, but instead bobbed along behind their captors, the toes of their boots a few centimetres above the floor. The Trancori binding Riker noticed his bleeding nose with an expression of disgust. "Are you injured? Is that your blood?"

"Some of it, yes," said Riker.

"Is this a serious injury? Will you survive?"

"Probably," said Riker. "I... I don't know." Clearly the Trancori knew little of human physiology, and Riker so no reason to educate them.

"Commander Riker needs urgent medical attention," said Troi. "Without proper treatment, that nasal haemorrhage could prove fatal." Riker resisted the urge to wink at her.

The leader looked a little unsure. "It will be seen to. If you co-operate."

"This is an outrage," said Picard. "We are a peaceful diplomatic mission! I demand to speak to your superior!"

"You are in no position to make demands," said the leader. "But you needn't worry. I'm sure ey will be very interested to talk to you."

The Trancori exited through the hole they'd cut, taking their captives with them. As they assembled on the narrow walkway ran around the outside of the elevator, another elevator rushed past in the gloom on the other side of the shaft. There was enough space for several elevators to use the shaft simultaneously, each one riding within its own complex cage of guide-rails and power conduits. Riker peered over the low handrail. The shaft seemed to disappear into infinity in both directions.

"Oh no," said Troi, who had never liked heights. "If you think I'm..." She was cut off by one of the Trancori picking her up and dumping her over the edge. Her scream quickly dwindled as she fell. Her guard followed immediately after, twisting in mid-air like a diver to fall head-down. Riker, not wanting to be pushed, swung a leg over the parapet and jumped.

They fell for what felt like hours, but was probably more like ten minutes. Riker had experienced anti-gravity sky-diving as part of his basic training at the Academy, but it felt like a long time ago. At one point, another elevator flashed past them, alarmingly close, and Riker wondered if it was the rescue team, heading up to see what had befallen them. If so, they were a little late.

Riker was just starting to wonder if the fall would never end when his AG harness came online with a soft him and an insistent tugging at the straps on his body as it slowed him down, until he and the others were hanging motionless in the air a few metres from the grimy wall of the shaft. There was a muffled banging and a rectangular hatch, hitherto invisible among the accretion of greebles lining the shaft, swung open with a shriek, revealing two more Trancori, in the same camouflaged uniforms as the others. They helped their comrades push the prisoners one-by-one through the narrow hatch.

"Now this really has gone too far," said Picard, eyeing the soot and grease streaking his dress tunic with distaste. "Your actions risk causing a major…" His speech was cut off as he was shoved head-first into the hatch.

Riker was next up. He wiped at his nose and upper lip with one hand. The bleeding seemed to have slowed considerably, but his hand still came away bloody. I must look a mess, he thought.

As the Trancori manhandled him towards the hatch, he flailed about, as though panicking. His guards pulled at him impatiently, but not before he had planted a bloody handprint on the wall, right next to the hatch. Then, with a final shove, he was through.

* * *

LaForge and Barclay were heading back to Engineering when it happened. One second they were walking down one of the Enterprise's long, gently-curving corridors, LaForge considering whether to invite Barclay to the next officers' poker game, and the next second a black, tentacled shape was bursting out of the wall and lunging straight at the two of them. Both men instinctively jumped back, reaching for their phasers. But before they had drawn their weapons, the entity had disappeared.

Barclay picked himself up, a little shaken. "You, you did see that, didn't you, sir?"

"See it?!" exclaimed Geordi, "the damn thing nearly knocked me over! I take it back, Reg – there's clearly something going on here."

"It all happened so fast," said Barclay. "I didn't really get a good look…"

"Me neither," said LaForge, "but the ship's internal cameras will have." He went over to the nearest console. "Computer, display recent security footage for deck seven, corridor section 23A… Thankyou. Show me camera nine, last two minutes."

LaForge and Barclay watched themselves onscreen as they rounded the corner, talking to each other. Then they jumped back simultaneously, nearly losing their balance, drawing their phasers and looking wildly around themselves.

"What the…?" muttered LaForge. He replayed the footage at half speed. Just before he and Barclay jumped back there was the briefest suggestion of a flicker, a transitory glitch, but other than that, nothing.

"But it was right there!" exclaimed Barclay. "Like a giant, black squid! And it went that way…" Barclay pointed to the wall.

Geordi nodded, moving closer to the wall the entity had disappeared through. "That's how I saw it," he agreed. He pushed gently on the wall panel. There was a popping sound and the panel fell away with a small puff of smoke, revealing fried circuitry behind it. "And bang on schedule, we've got another malfunction."

"I'll get right on it, sir," said Barclay.

"Thanks, Reg, but we need to work out what the bigger picture is here. I'm calling a meeting."

* * *

The tunnel in which Riker and the others now found themselves was extremely cramped, no bigger than one of the Jeffries tubes on the Enterprise, and even the diminutive Trancori had to duck down. Unlike the Jeffries Tubes, it had rails set into the floor, and a short train of miniature carriages was waiting a little way down the tunnel. The prisoners were loaded onto this, and they set off at high speed – faster than the trains were designed for, it felt like – into the darkness.

"This all seems a bit primitive," observed Picard, his teeth rattling as they hurtled over a particularly bumpy section of track. "I thought their technology was supposed to outstrip our own."

"Something tells me that most people don't come this way," said Riker. He was about to say more when the train ground to a halt and the lights went out. They waited silently in the dark for a few minutes. There was the sound of another train nearby, and a wash of light from somewhere ahead as it crossed their tunnel. The Trancori waited a few more minutes, then, when they were sure the coast was clear, turned the lights back on and started moving again.

"Seems they're anxious to avoid detection," said Riker.

"Which would suggest we're dealing with common criminals," mused Picard. "Perhaps they intend to hold us for ransom."

Troi shook her head. "I don't get the sense that they think of themselves as criminals. They're disciplined, and believe that they're doing is for the greater good. I don't know what their motive is, but it's certainly not money."

"Interesting," said Picard. "I'm not sure if that makes our situation better or worse."

"Worse, I'd say," said Riker. "Always harder negotiating with someone who's fighting for a cause."

"And they're frightened of us, too," said Troi. "That comes across very strongly. "Frightened and angry."

* * *

 _Second Officer's Log, Stardate 42313.6: I have been left in temporary command of the Enterprise while the Captain and First Officer are on the planet below. We lost contact with them more than two hours ago and all attempts to contact them have been unsuccessful. The Trancori Government has been unable to assuage our fears._

"You're saying that the delegation never reached you?" Data asked Director Adelma, the Tancori on the viewscreen. The exact nature of the Trancori hierarchy was unclear, but judging by eir richly-embroidered, golden robes, and the way the others deferred to em, Adelma was pretty important.

"That's right," said Adelma, apologetically. "I sent Administrator Dolano – one of my most trusted subordinates – to meet them on the upper levels. A great honour for him, you understand. We have awaited visitors from the stars for so long, some of us were starting to lose hope. They were supposed to get the elevator directly here, but it appears they were, well, waylaid."

"Hmm," said Data. "Please elaborate."

Director Adelma plucked at the cuffs of eir robes. "Well, one doesn't like to jump to conclusions, but they appear to have fallen prey to terrorist activity."

"Who are these terrorists?"

"Well, I couldn't say for sure..."

"Please speculate," said Data. "For you to hypothesise that the away team has fallen prey to terrorist activity, it seems likely that you have some terrorists in mind."

"Well, there are those whom... our people do not travel the Outer Darkness. As a result we get very few visitors from other planets. My government have for a long time forseen a time when this would change. It was all fortold, you know. However, there are extremist elements that take an isolationist stance, and maintain that contact with other species is neither possible nor desirable. Some of the real fundamentalists refuse to even believe that other species exist."

"But we're here," said Data. "That may not be desirable, but surely the possibility is not in doubt."

"They're fanatics! Ruled by superstition! Denying our most sacred texts from the age of space! And they hate and fear anything that threatens their medieval worldview. They would do anything to stop your delegates appearing in public."

"Do you believe that they have killed our away team?"

There was a pause. Director Adelma looked somewhat taken aback. "Well, we very much hope not, of course. I have my best people on the scene right now, looking into it."

"Good," said Data. "I shall transport a security team to their location to assist."

"I'm sure that won't be necessary," said Adelma. "With the profoundest respect, I'm sure that even the most exalted outsiders, unfamiliar with our procedures, could contribute much."

"Nonetheless," said Data. "I Insist. When we return to Federation Headquarters, it will be much easier if I can base my report on the first-hand testimony of my own crew. Your co-operation in this will be viewed most favourably by Starfleet Command."

There was another long pause. In the end it was Adelma who broke the silence. "Very well. I will permit a small security detachment to observe my team. But they must do nothing to impede our investigation."

"Agreed," said Data, turning to Whorf. "Mister Whorf?"

Whorf nodded. "Right away, sir."

* * *

There were nineteen members of the Engineering crew squeezed into the Observation Lounge. Commander LaForge had opened up the meeting to anyone not in charge of critical systems that shift, but he hadn't been expecting so many. Clearly word had got around.

"I've seen them, I tell you!" said Ensign Chaudhury, for the third time. "They come out of the walls! Black. Mostly tentacles." He shuddered.

Several other people nodded vigorously. "I've seen them too," said Petty Officer Spalding, a young software specialist who was normally pretty unflappable. It wasn't like her to panic. "In the shuttle bay... I don't like to work alone any more, if I can avoid it."

"Okay, so there's something out there," said LaForge. "Maybe I wouldn't have believed it, but I saw one with my own eyes – well, my visor – less than an hour ago. Practically ran into Barclay and me. And yes, there was a hardware malfunction right after, in the same spot. Which backs up what some of you are saying about these... entities causing breakdowns. Apparently. But we still don't know what's going on. We're engineers, people. We need hard data to work with."

"They're eating the ship!" said Chaudhury. "Eating it from the inside out! They're all around us, Sir."

"So why aren't they showing up on the security cameras?" asked Barclay. "That would seem, from my point of view, to be a big part of the puzzle. I saw the footage of the Commander and myself encountering the entity on deck seven. It was like there was nothing there."

"We've got no footage of them at all," said LaForge. "I checked. But there isn't an inch of this ship that isn't monitored."

"I wondered that, too," said Spalding, the software specialist. "But they move fast – blink and you miss them."

"The internal cameras record at sixty frames a second," pointed out Chaudhury. "They don't miss much."

"Those cameras are smart," said Spalding. "Maybe too smart. They don't just dumbly record everything. They try to make sense of what they're seeing – there's a lot of signal-processing that goes on even before the footage is committed to the ship's memory. If some shapeless, black thing just appeared for a few frames before disappearing again, the image-processing module wouldn't understand what it was looking at. It could just interpret it as a transitory glitch – filter it out like any other noise."

"It's possible, I suppose," said LaForge. "It sounds like you've given this some thought, Ms. Spalding."

"Aye, sir. With your permission, I'd like to modify the error-correction algorithms the internal camera systems use. If we can get them to preserve the raw data we might get some footage of one of these things."

* * *

Riker shifted on the bench he and his fellow officers had been handcuffed to. It was too low, like sitting in a child's chair, and it was making his butt ache. Apparently the Trancori base didn't run to purpose-built detention facilities – which Riker decided was a good sign, unless it was because they ate their prisoners – so they'd been chained up in the corner of a large room that served as a sort of staging area for uniformed personnel departing or arriving on the little. In the two hours or so they'd been there, several groups of Trancori, armed and equipped like the ones who'd hijacked the elevator, had set out on patrols. In the centre of the room, surrounded by crates and bundles of gear wrapped in plastic, three Trancori sat behind computer terminals, looking up to shout orders as the others came and went, and casting occasional suspicious glances over to the Starfleet officers in the corner.

Riker's ability to tell what was going on was hampered by the Trancori having taken his comm-badge. Without the badge's translator function, the Trancori language just sounded like a mess of angry jabbering. As well as their comm-badges, they'd taken their tricorders, even the rank insignia from their collars, in case they had some hidden function, but they'd missed the slim form of Riker's type one hand-phaser, tucked into its custom-tailored pocket under his left arm, inside his dress tunic. Obviously, this was useless to him all the time his hands were chained, but it gave him hope, knowing it was there.

He looked along the bench to see how the others were bearing up. They had to be careful what they said – they might not be able to understand the Trancori, but that wasn't to say that they didn't have their own translation devices.

"Feeling restless, Will?" asked Picard, catching Riker's eye.

Riker laughed hollowly. "I can't say this was the reception I was hoping for. When do you think we're going to meet the management? I've got one or two complaints."

Picard nodded. "I can't say I relish the prospect of interrogation, Number One, but we do need some answers ourselves..." He turned to the Trancori staffing the desk. "Hey there!" he called. "I demand to speak with your leader! I was told that ey wanted to speak with me!"

This didn't immediately seem to provoke any reaction beyond a contemptuous snort, but a few minutes later one of the Tancori got out from behind eir desk and left the room. A little later ey were back with some guards.

"Commandant Zang will see you now," ey said.

* * *

Lieutenant Whorf looked up, then down the seemingly-endless elevator shaft. "Which way do you think they went?" he asked the head of the Trancori team.

Investigator Polto made a head-waggling movement that Whorf guessed was the Trancori equivalent of a shrug. "I don't know. But if I had to guess, I'd say down. As you know it's pretty inhospitable on the upper levels. I've always suspected that there's a rebel base further down, deep inside our habitable zone."

"Very well," said Whorf, summoning his team. "We will explore downwards." He activated his anti-gravity harness and vaulted over the parapet. He had been hoping to use his tricorder's olfactory sensors to pick up a trail of human pheromones, but there was a powerful breeze blowing up the elevator shaft, and any forensic evidence that might once have lingered in the atmosphere was long gone. Instead, Whorf and his two security officers descended slowly, scanning the shaft with their tricorders and playing powerful flashlights over the walls, looking for visible clues. It seemed pretty hopeless – the technology lining the walls of the shaft was so alien in appearance and mysterious in function that Whorf had no idea what he was looking at. He was just about to give the order to return up the shaft when Crewman James called up from a couple of hundred metres below. "Sir! I've found something!"

Whorf swooped down. Clearly visible in the beam of James's flashlight was a dark stain, smeared but clearly visible as a hand-print. Petty Officer Clarke was already there, scanning the print with her tricorder. "Human blood," she said. "Yes. Match for Commander Riker."

Whorf tapped his comm-badge, hailing Investigator Polto. "You're going to want to see this."

Crewman James was examining the surrounding area. "Just the one print. Looks almost... deliberate, wouldn't you say?"

"Perhaps he left it as a sign," said Whorf, now close enough to the wall to run his hands over the grimy surfaces. "Hey! There's a hatch here!"

He turned, seeing Polto floating down the shaft to join them. "Polto! Help me get this open!"

Polto hurried forward, pulling a tool from eir belt, but ey looked unconvinced. "It's just a junction box," ey said. "It won't go anywhere."

"That's Riker's blood." Said Whorf. "I want it open."

Polto did the head-waggle shrug and swung open the hatch to reveal a shallow box cluttered with primitive-looking electrical switchgear. "See I told you..." ey began, but Whorf held up a hand for silence, watching the screen of his Tricorder as he pointed it into the cupboard. "Olfactory sensor confirms it," he said. "Three humans went this way – their scent is still in the box."

"Well, they're not there any more," said Polto. Whorf ignored him, aiming a powerful kick into the box. There was a crack and the entire back wall of the box fell inward, revealing the start of a long, narrow tunnel. Twin rails were set into the floor, gleaming in the beam of Crewman James' flashlight.

"They went this way," said Whorf, a note of triumph in his voice.

Investigator Polto was already on the comm-link to his headquarters. "Send backup to my location. I'll need an armed response team. We've found the Rebels' tunnel network."

* * *

An alarm went off, shaking Commander LaForge from his reverie and nearly making him spill his coffee over the engineering console. He put his mug down and checked the screen. When Petty Officer Spalding had reprogrammed the internal cameras, she'd repurposed the error-detection algorithms to sound an alarm when they detected the kind of fast-moving, amorphous shapes that they previously would have filtered out. A cluster of cameras in the main reactor room – just down the companionway from where he was now – had seen something. He silenced the beeping and patched through the live feed. Of course, there was nothing to see now, just a couple of technicians doing something routine in the corner, apparently oblivious to anything unusual having happened. LaForge pulled up the last few seconds of footage in another window, and saw the Entity immediately. A tentacled blur, lunging across the reactor room, and then gone. LaForge paused, skipped back, viewed it frame-by-frame, skipping between cameras to get the best view.

In the first frame nothing was out of place. In the next, a dark stain had appeared on one of the bulkheads. In the third frame, the dark patch had extruded into three dimensions, extending long, curling tendrils from the wall, looking like something between a giant squid and a blob of ink dropped into water. The cameras were set to record at sixty frames a second, so whatever this thing was, it was moving fast. By the fourth frame the Entity had detached from the wall and was headed for the warp reactor, and by the sixth its tentacles were reaching for the reactor itself, straight through the transparent radiation shielding surrounding it and caressing the core itself.

"Get your tentacles off my warp core, you filthy monster," muttered LaForge. Clicking through the next few frames, he got the impression that the entity was feeding on the energy of the warp reactor. The tentacles pressed against the core and swelled, engorged as the blue glow within the core itself flickered and dimmed. Less than half a second's-worth of footage later, the entity had detached itself from the warp core and was headed back to the spot it had emerged from. The two technicians in the corner, meanwhile, hadn't moved visibly. Clearly they'd noticed nothing amiss.

LaForge looked back at the live feed. Whatever the technicians – Crewmen Ling and Mendar, a Bolian – were doing, they were deeply engrossed in it. Nothing seemed wrong, but… looking at the readouts from the systems monitoring the core, some of the parameters were fluctuating. Not quite enough to trip any alarms, but heading that way.

As LaForge watched the numbers, they climbed into the red and, sure enough, the alarm sounded, this one coming from the reactor room itself. LaForge was already on his feet and heading that way. In the reactor room, Ling and Mendar had finally looked up from their task, trying to spot the reason for the alarm.

"An entity just passed right through here," said LaForge, running to the nearest console to check the fault-warning system. "Had its greasy mitts all over my reactor. Damn – anti-matter containment's failing. Ling! Vent the..."

But he was too late. A fluctuating force-field surrounding one of the anti-matter injectors flickered, guttering like a candle flame in a breeze. It was only for a microsecond, but long enough for a deadly blast of radioactive plasma to explode out of its containment vessel, lancing through the physical shielding like a blowtorch through butter. The shielding vaporised instantly, exploding in a ball of incandescent gas and white-hot shrapnel that fired through the room like bullets. A thousandth of a second later the emergency containment field slammed into place and the computer started a crash reactor shutdown, but the damage was already done. Fire-suppression systems sprang into action, covering the affected area with foam.

Geordi picked himself up from the floor, his ears ringing. His visor seemed to be working OK, although he couldn't see much through all the smoke and foam covering everything.

"Everyone OK?" he shouted, his voice sounding muffled and distant.

"I, I think I am," said Mendar. "Crewman Ling, though…" He turned to look at his crewmate, his face paling. LaForge knew there was something seriously wrong before he looked at Ling. "LaForge to sickbay," he said. "Explosion in Engineering. Standby for emergency medical transport." He made his way over to Crewman Ling, lying in a crumpled heap. Ling moaned and tried to move.

"Easy there," said LaForge. He couldn't see the extent of Ling's injuries due to the foam that was covering him, but a lot of it was stained pink with blood, and what he could see of Ling was deathly pale. "One to transport to sickbay," he said. "Target on Crewman Ling. Looks like he's losing a lot of blood."

"Understood, and standing by," said Doctor Pulaski. "We'll look after your man, Mister LaForge."

Once Ling was beamed was beamed safely away, LaForge turned his attention to his precious ship, only dimly aware of the damage-control team rushing into the room around him. There were a least three redundant safety systems that should have made what had just happened impossible. The only cause he could think of was a massive, sudden degradation of the very material that the warp reactor was made of, as though tritanium plating had been magically replaced with cardboard. It was, to put it mildly, disturbing.

LaForge went over to the bulkhead he'd seen the creature emerge from. It wasn't marked, or visibly altered in any way, but it crumbled beneath his fingers when he reached out to touch it, the texture of cookie dough. The only time he'd seen anything like this had been with extreme cases of transporter malfunction – lab tests, pushing transporter technology way past design specs, rather than anything that happened in the field. He tapped his comm badge. When it came to weird applications of transporter technology, there was an expert on board. "LaForge to O'Brien. Can you meet me in the reactor room, Chief?"

* * *

Riker frowned across the table at Commandant Zang. He'd been trained how to handle hostile interrogation, but this wasn't exactly going by the book.

Captain Picard had ordered Riker and Troi to be as open as possible with their captors – they were not a hostile force, and had nothing to hide. So, apart from certain classified information regarding the Enterprise's combat capabilities, Riker was willing to tell Zang whatever ey wanted to know. He'd been hoping that this would mean that things would proceed without too much hassle. However, it seemed that he was actually sharing more information than Zang seemed comfortable with. Riker was starting to wonder whether Zang actually wanted Riker to tell em anything at all. When, in answer to a question about who he worked for, Riker began describing the constitution and member species of the Federation, Zang actually cut him off.

"Nonsense!" snapped Zang. "Fairytales and rubbish!" Riker didn't have to be a Betazoid to see that his answers had unnerved Zang.

"Admit it," said Commandant Zang. "You people aren't from the Outer Darkness at all. All this talk of arriving here on some magical 'ship' that can fly between worlds..."

"Your people used to do it," observed Riker.

"More fairy tales," said Zang. "No rational person believes any of those stories any more. No, you're as Trancori as I am."

"Oh, come on!" said Riker. I've got to be half a metre taller than any of you! Have you even seen a beard before?"

"I'll admit your appearance is somewhat freakish. You have clearly gone to great lengths to perpetrate this deception."

Riker rolled his eyes. "It's you who's going to great lengths, to make up these convoluted excuses for the obvious. The Enterprise is up there, in orbit, if you'd just look." He sighed. "To be honest, I don't care what you believe. I've got no argument with you people. Or I won't, once you release me and my companions. We're here on a mission of peace."

"Still you persist with your blasphemy," said Zang. Ey lowered eir voice. "I'll have you know that there are people here who would kill you for what you have said here."

"For telling fairy tales, you mean? Why? What's the threat?"

Zang looked as though ey was about to answer, then looked up at the two guards stationed by the door. "Leave us," ey said. "I wish to interrogate the prisoner privately."

Once the guards had left, Zang pressed a few buttons on the auto-translation device on the table between them. "This conversation is now off the record," he said.

"This the part where you try to beat the truth out of me?"

Zang looked momentarily confused. "I'm not a barbarian. And I'm starting to think you believe what you say. Even if it is nonsense. You're lucky my people picked you up, and not one of the other cells."

"Who are you guys, anyway?" asked Riker. "Some kind of rebel outfit?"

"You really don't know?"

"I told you. I just arrived on the planet this afternoon."

"DO NOT SAY THAT!" yelled Zang, pounding eir fist on the table. "If the others hear you, they will kill you."

"Why are they so scared of the idea of alien visitors?"

"The only creatures that can live in the outer Darkness are the Warp Demons. We thought we were safe from them, down here, that they couldn't reach our planet. But if you're really from the Outer Darkness then you're one of them, and we are no longer safe."

"Is that why you don't leave your planet any more? Because of these Warp Demons?"

Commandant Zang looked at Riker uncertainly. "There's nothing for us out there. Whatever Director Adelma and eir followers might want us to believe."

"I see," said Riker. "It seems to me that my colleagues and I have become embroiled in a theological dispute."

Zang glanced down at the translation device."Theological...? I suppose that's one way of describing it." Ey paused before continuing. "Say, for the sake of argument, that I believed you really were from the outer Darknerss. I still wouldn't let you go back to Adelma, let him parade you about in front of the world's media. Ey would use you, you know, to prove that eir mad dreams of leaving this world have been justified all along..."

"Maybe they are," said Riker. "There's a whole universe out there. You've got the technology to explore it. You just need the resolve to make the first step. Unless you'd rather spend the rest of your lives scrabbling through these tunnels, like rats..."

Zang was about to reply when one of the guards burst in without knocking.

Zang spun around angrily. "I told you we were not to be disturbed!"

"It's the tunnels, sir! Government forces have found their way in. We're under attack."

Zang said something that the translation device chose to leave untranslated. "Keep a close eye on the prisoner," he snapped. "I'll be back!"

"It's just not turning out to be your day, is it?" said Riker.

* * *

Whorf ducked back around the corner as a section of wall near his face exploded under a barrage of phaser fire. The Trancori weapons were crude, but lethal at close range. He gritted his teeth and peered back around the corner, firing his own phaser and felling his assailant. It was difficult to tell the size of the opposing force they'd encountered, but it was clear that Whorf and his team were surrounded and massively outnumbered. Luckily, the narrow tunnels prevented anyone from attacking more than two abreast, limiting the advantage of numbers somewhat. Whorf had already shot five of the attackers, and his security team the same again, their stunned bodies littering the tunnel floor. But still they came. The Trancori on both sides were clearly experts in this kind of close-quarters fighting, and fought with impressive ferocity and determination. Whorf and his team had trained in how to repel boarders in similar tactical situations, but they were on unfamiliar territory.

It had taken them almost an hour to make it this far down the tunnels, carefully checking the scent at each junction, bent almost double. In the confined surroundings, the olfactory sensor on Whorf's tricorder was far better at following the trail of human pheromones left by the other Starfleet officers. Riker, in particular, left an unusually strong androstenone trace. Whorf wondered whether this was why so many human females were attracted to him.

It had been slow, uncomfortable work and Whorf had been distracted by his aching back when the trap had been sprung – a squad of rebels attacking from a turn-of Whorf and Polto's team had passed, having written it off as a dead end. They'd taken out two members of Polto's team instantly, forcing the others forward and straight into the second squad of rebels waiting around the corner.

Only Whorf's quick response had stopped the ambush becoming an all-out massacre. Seeing that they were about to be squeezed out of existence by the two squads of rebels, he and his personnel had charged the ambushers in front of them, forcing them back around the next corner and giving Polto's people enough space to regroup and mount a defence of their rear. Whorf and Petty Officer Clarke had held the corner – a ninety-degree bend, which gave them something to hide behind, at least. Polto and eir troops had less in the way of cover – only the shallow niches set into the walls at intervals – but they had heavier weapons, and at the moment were keeping the attackers to the rear at bay with sheer firepower.

Whorf turned back, waving to get Polto's attention through the noise and smoke. They both crawled over and met in the middle.

"We can hold them off for a while," said Polto.

"But not indefinitely," said Whorf. "And we can't break through their defences. Let's look at that map again."

Polto pulled out a handheld device and projected a map onto the floor. It was incomplete, and out-of-date, but so far it had proved reasonably accurate, if lacking in detail.

"I think we're here," said Polto, pointing.

Whorf nodded, muttering something in Klingon. "Of course. It's the exact spot I'd choose to mount an ambush. I should have seen this coming."

"There'll be time to blame yourself later," said Polto, wincing as a stray phaser beam crackled in the air a few centimetres above his head. "But right now we need to get out of here."

Whorf pointed to a tunnel on the map, running parallel to their own. "If we could break through here, we could outflank the rebels in front of us, bypass the whole ambush before they realise what we've done."

Polto thought about it, studying one of the niches in the tunnel walls. "We're carrying breaching charges that might do it. I'll set it up. You tell your people."

* * *

O'Brien ran his hand over the crumbling surface of the bulkhead in the reactor room. "I see what you mean, Commander," he said. "Cookie dough. Never seen anything like it."

"I was kind of hoping you had," said LaForge. "It put me in mind of transdimensional displacement."

"I'm just a simple transporter tech, Sir," said O'Brien. "I avoid sending things through any dimensions other than the usual three. But yes, it can happen, theoretically. These… entities that have been skulking about the place – you think they're extra-dimensional?"

"It's one theory," said LaForge. "What I want to know is, if such a creature was to force itself into our own dimension…"

"Yes, I guess it would leave a mess a lot like this," said O'Brien. "The two forms of matter would be incompatible on a quantum scale. The creature itself wouldn't feel anything, but the bulkhead it was passing through…" O'Brien gestured to the damage the two men were facing. "A lot of the original mass just isn't there any more. It's been shunted out of our three dimensions."

"So what does this tell us about the creatures themselves?"

"Beats me," said O'Brien. "But if they keep walking through the walls like this, we're not going to have much ship left."

"There is a legend on my homeworld," interjected Crewman Mendar, looking up from his assigned duty of scanning for microfractures in the core shielding.

"Well, out with it, son," said O'Brien.

"It tells of a great engineer who built a ship that could go faster than anything before or since, using a radically different interpretation of warp theory. But there was something… forbidden about the way it generated a warp field. It angered the Unspeakable Ones, who lurk in the spaces between the worlds, and they swarmed upon the ship, and destroyed it."

"Okay," said O'Brien. "Sounds a little sketchy, though…"

"Yes, sir. It happened centuries ago, if it happened at all. But a few historians think there's some truth in it. Some early theoreticians on Bolarus came up with completely different solutions to the warp field equations. Most engineers say there's no practical application, but the historians claim that if you did manage to build a working engine based on that model, it could tear a rift in space. Things could cross through, from other dimensions, Sir."

LaForge and O'Brien exchanged a look. "I think I'd know if my warp field was tearing a hole in space," said LaForge. "And it wouldn't explain why we were just getting this problem now."

"It would if it wasn't our ship what was doing it!" said O'Brien. "Maybe it was the Trancori ships, back when they had space flight."

Crewman Mendar nodded eagerly. "It would explain why they gave up space travel! No wonder they're scared – if their ships all had the same problem, then the entire volume around their planet would be full of these rifts, like a spider's web."

"And we flew straight into it," said O'Brien, with a shudder. "Gives me the creeps just thinking about it. You've got to admit, sir, it fits with the evidence."

LaForge shrugged. "It still sounds pretty far-fetched to me," said LaForge. "But it's the first testable theory we've come up with. I need to talk to Commander Data. We should know pretty soon whether your old legend's got any truth in it, Mister Mendar."

* * *

It had been less than ten minutes since Commandant Zang had left Riker to deal with the attack. During that time, the guard left with Riker had grown increasingly restless, stealing frequent glances towards the door. From outside there were the noises of squads of fighters running to the staging area, and hurriedly-shouted orders.

Riker met the guard's eye. It was difficult to tell with this species, but Riker guessed ey was young. Ey looked back at Riker, an undisguised expression of disgust on eir face.

Riker smiled. "You don't want to go out there."

"Don't tell me what to do, freak."

"Much safer to stay here, with me. When my friends rescue me, I'll tell them that you're harmless. They won't hurt you."

The Trancori snarled. "I'll show you 'harmless', traitor!" Ey stepped forward, but was interrupted by the sound of an explosion, echoing down the tunnels. Ey stood, looked again towards the door, eir anger replaced by fear.

"Sounds like my friends are getting nearer," said Riker. "I'll let them know you were co-operative."

"Damn you and your friends," said the guard, drawing eir weapon.

There were two more explosions, close together.

"Damn your friends," repeated the young Trancori. "I'll show them." Ey left the room, locking the door behind eirself.

As soon as he was sure that the guard wasn't coming back, Riker stood, pulling the phaser from his tunic. A short burst aimed at the door reduced the lock to molten metal. Riker kicked the door open and stepped out into the corridor. A door immediately opposite had a small window set into it at Trancori head height. Riker stooped to peer through, and saw a sparsely-furnished storage room with Picard and Troi sitting on the floor, their backs to the wall. Riker phasered through the lock and pushed the door open.

Picard looked up. "Good show, Number One. Let's get out of here, shall we?"

* * *

One of Polto's team took a bundle of tubes from eir pack, unfolding it to form a square frame about a metre across. As ey attached it to the back wall of one of the niches in the tunnel, ey explained that it contained a shaped charge that produced a focussed jet of plasma, capable of cutting through most materials to a depth of about half a metre. Ey added that it was going to be deafeningly loud when it did its thing, especially in such a confined space.

"Better deaf than dead," said Whorf.

He'd just made his way back to Clarke and James's position when the charge went off behind him, as loud as the Trancori had said, and filling the tunnel with smoke and dust. Whorf stepped out around the corner, while the ambushers were still – hopefully – surprised by the detonation, and started firing into the gloom. "Fall back!" he yelled to his subordinates. "Follow Polto!"

They were doubtless as deaf as he was, but seemed to get the gist. Whorf fired a few parting shots before following. Inspector Polto was crouched by the breach, counting everyone through the hole. Before following the others, ey pulled the pins on a couple of grenades and lobbed them in each direction along the tunnel. "Proximity sensors," ey explained to Whorf, once they were safely through the hole. "Should discourage anyone from following us."

The Trancori led the way while Whorf and his people brought up the rear. They had had only just started moving along the new tunnel when they heard the two grenades going off in quick succession, followed by a rumble that sounded like part of the ceiling coming down. Whorf and his people stopped, turned back while Polto's team went ahead, waiting around long enough to confirm that they weren't being followed.

They caught up with the Trancori team to find them huddled, with bated breath, against a wall, while one of them peered around the corner ahead using a small mirror on a stick.

"There's a door ahead," whispered Polto as Whorf joined em. "A big, armoured one. Couple of sentries outside. Looks like we've found the rebel base." Ey nodded at one of eir team who was crouched nearby, unarmed but for a wickedly-curved fighting knife in one hand. The Trancori crept around the corner. There was the sound of a brief scuffle, a grunt, and a long, drawn-out sigh. The trooper with the mirror looked round at the others. "Doorway's secure."

The two sentries were dead, their killer stood over them, wiping the blood off eir knife. These Trancori might be small but they are formidable warriors up close, thought Whorf. Their way of fighting was not the Klingon way, but it was undeniably effective.

Polto held eir handheld device up to the steel door, scanning what was on the other side as best ey could. "There's an open space on the other side," ey said. "A big room. Detecting several life-signs, and I don't think they're all Trancori."

Whorf pulled out his tricorder. "Yes, Riker and the others passed this way. We'll need to move quickly to secure the hostages. Starfleet doctrine for a situation like this calls for sudden and overwhelming force."

Polto cast an eye over the four remaining members of his team. "Do we have enough people? I can call for reinforcements."

Whorf shook his head. "We need to move now. Before the forces behind us can regroup."

"Very well," said Polto. "Trooper Tanari, another breaching charge, please."

* * *

Commander LaForge realised that he was holding his breath as Commander Data ran a final check on the program they'd just written together, reconfiguring the deflector array to emit a wide beam of Theta radiation. This would – hopefully – excite any nearby anomalies in the space-time continuum, causing then to fluoresce in the electromagnetic spectrum; they would become visible, at least to a properly-calibrated sensor array.

"I believe we're ready," said Data. "Computer, activate program Data 42313 Epsilon. Display results as overlay on main viewscreen."

The space around Trancor suddenly glowed blue, the planet caught at the centre of a web of frozen lightning.

"Good grief," exclaimed O'Brien. "They're everywhere!"

Data panned the view around, following the network of rifts as they radiated out from the planet and into deep space.

"Wait a minute," said LaForge. "There's something moving in there. Can we get a closer look at one of the rifts?"

Data zoomed in on one of the nearby tears until it was like looking down into a glowing blue canyon. Deep in the canyon, millions of tentacled things writhed and slithered over each other, like maggots crawling in a wound. "Okay, I've seen enough," said LaForge. "You can zoom out again."

Looking at the web of rifts as a whole, it became clear that they never extended all the way to the planet, but rapidly fizzled out as they approached the surface, encircling but never quite touching the planet itself.

"Interesting," said Data. "The frequency and scale of the rifts has an inverse-square relationship to the strength of the local gravity field."

"Would make sense," said LaForge. "If I remember my multi-dimensional geometry correctly, it would be impossible to tear a hole between dimensions where space-time was too sharply curved."

"Well I don't know about that," said O'Brien. "But if a little space-time curvature's all that it takes to scare these beasties off I could reconfigure the deflector array to project a gravimetric distortion field."

"Brilliant," said LaForge. "That's the first piece of good news I've had since we got here."

* * *

"We need our comm-badges," said Picard. "Without them, we have no way of signalling the Enterprise, even if we do reach the upper levels."

"They're in that desk, in the first room they held us in," said Troi. "But we can't just stroll in and ask..."

Riker held up his phaser. "I'm sure I can persuade them."

Picard nodded reluctantly. "Very well. But let us try to keep any violence to a minimum. If you'll remember, Number One, we beamed down here on a diplomatic mission."

"That feels like a long time ago," said Riker. "But I take your point."

The three of them crept down the corridor, back towards the staging area. It sounded quieter than before – Riker guessed that most of the rebels were off fighting the government forces. It was deserted but for the two Trancori behind the desk. Riker stepped out from behind a pillar, phaser aimed at the nearest Trancori.

"Hands where I can see them, please," he said. "This weapon is set to kill."

The Trancori, completely taken by surprise, did as they were told.

"Very sensible," said Riker. "Now throw over our communicators. The badges you took from our uniforms."

No sooner had Riker caught his comm-badge and clipped it to his uniform tunic, than a shout from behind made him spin round. An armed squad of rebels, led by Commandant Zang emself, had emerged from the corridor behind the Starfleet officers and walked straight into Troi and Picard. Zang now had them at gunpoint, while Riker still had his phaser trained unwaveringly on the Trancori behind the desk.

"It seems we have something of a standoff," said Picard. "Why don't we all calm down and see if we can talk about this?"

Zang snorted contemptuously. "Never! Guards! Disarm this man!"

Two of the Trancori stepped towards Riker. He was just wondering what he was supposed to do next when there was an explosion that knocked everyone off their feet.

Riker sat up, coughing, to see Whorf emerging from the smoke, followed by two crew from the Enterprise and a squad of Trancori security officers.

"Doesn't anybody just use a door around here?" asked Riker.

"It seemed expedient to make a dramatic entrance, sir," said Whorf, as the security team rushed forward to subdue the stunned rebels.

"Well, I can't fault your timing," said Riker.

* * *

 _Captain's Log, Stardate 42315.6: Despite the inauspicious start, preliminary negotiations with the Trancori are going well, with both factions having been persuaded to visit the Enterprise to begin exploratory peace talks. It also seems that, in my absence, my engineering officers have hit on a technical solution to the blight that's been keeping Trancor isolated for so long._

Commander LaForge looked down the table at his audience, a mix of his fellow officers and Trancori delegates. He'd just concluded a lengthy technical presentation on the generation and use of gravimetric distortion beams in eradicating the trans-dimensional rifts and the entities that lurked within them. It was difficult to tell how it had gone down with the Trancori. Or even if they'd understood it.

Finally, Director Adelma spoke. "This seems remarkable in theory. Truly remarkable. But when will you be able to put it to the test?"

"Already on it," said LaForge. "We've been sweeping the area with the gravimetric beam at regular intervals since we made the discovery, and there's been no more sightings of the entities on board, and no mystery malfunctions, either. It's too early to say for sure, but I think we may have found a solution to your problem."

"Extraordinary," said Commandant Zang. "Just being here, one of the first Trancori to leave the planet for a thousand years, is incredible enough, but now you're saying you can give us the tools to repair the damage we've done to space itself – to make travel to the stars possible."

Picard nodded. "And hopefully to heal the rifts in your society, too. I understand what a big step you've both taken in coming on board, just to sit around this table, but hopefully it is the first step towards peace."

THE END


End file.
